Vikas TU
Last Activity: 4 Years ago
tan x + tan 2x = tan 3x
Now let us simplify, tan x + tan 2x = tan 3x
tan x + tan 2x – tan 3x = 0
tan x + tan 2x – tan (x + 2x) = 0
On using the formula, tan (A+B) = [tan A + tan B] / [1 – tan A tan B]
Therefore, tan x + tan 2x – [[tan x + tan 2x]/[1- tan x tan 2x]] = 0
(tan x + tan 2x) (1 – 1/(1- tan x tan 2x)) = 0
(tan x + tan 2x) ([– tan x tan 2x] / [1 – tan x tan 2x]) = 0
Now, (tan x + tan 2x) = 0 or ([– tan x tan 2x] / [1 – tan x tan 2x]) = 0
(tan x + tan 2x) = 0 or [– tan x tan 2x] = 0 tan x = tan (-2x) or -tan x tan 2x = 0
tan x = tan (-2x) or 2tan2 x / (1 – tan2 x) = 0
[Using, tan 2x = 2 tan x / 1-tan2 x] x = nπ + (-2x)
or
x = mπ + 0 3x = nπ
or
x = mπ x = nπ/3 or x = mπ
∴ the general solution is x = nπ/3 or mπ,